Light emitting LEDs devices comprised of LED chips that emit light at a first wavelength, and a tinted thin film layer over the LED chip that changes the color of the emitted light. For example, a blue-light emitting LED chip can be used to produce white light. The tinted thin film layer beneficially consists of ZnSe, CeO2, Al2O3, or Y2O3:Ce that is deposited using a chemical vapor deposition process, such as metal organic chemical vapor deposition (MOCVD), atomic layer chemical vapor deposition (ALD), plasma enhanced MOCVD, plasma enhanced ALD, and/or photo enhanced CVD. Suitable CVD precursors include Alkoxide, &bgr;-dikeonate, Metalloscene, Alkys, DMZn, DEZe, H2Se, DMSe, TbuSe, and DESe.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A light emitting diode (LED), comprising: an LED chip having a first electrical contact and a second electrical contact, wherein the LED chip emits blue light having a first wavelength in response to applied electrical power; and a yellow thin-film layer over the LED chip; wherein the yellow thin-film layer and the blue light interact to form light having a second wavelength.
2. An LED according to claim 1 , wherein the yellow thin-film layer is selected from a group consisting of ZnSe, CeO 2 , Al 2 O 3 , and Y 2 O 3 :Ce.
3. An LED according to claim 1 , further including an inner passivation layer disposed between the yellow thin-film layer and the LED chip.
4. An LED according to claim 1 , wherein the yellow thin-film layer and the blue light interact to form white light.
5. An LED according to claim 1 , further comprising an outer passivation layer over the yellow thin-film layer.
6. An LED according to claim 1 , further comprising a first bonding wire connected to the first electrical contact and a second bonding wire connected to the second electrical contact.
7. An LED according to claim 1 , wherein the LED chip has a lateral topology structure.
8. An LED according to claim 7 , wherein the LED chip includes: a substrate; an n-type GaN structure on a second surface of the substrate; an active layer having at least one quantum well on the n-GaN structure; a p-type GaN layer on the active layer; a transparent conductive layer on the p-type GaN layer; a p-type electrical contact on the transparent conductive layer; and an n-type electrical contact on the n-type GaN structure.
9. An LED according to claim 8 , wherein the p-type electrical contact forms the first electrical contact and the n-type electrical contact forms the second electrical contact.
10. An LED according to claim 8 , wherein the n-type GaN structure includes an n-type GaN buffer layer.
11. An LED according to claim 8 , wherein the substrate is sapphire.
12. An LED according to claim 1 , wherein the LED chip has a vertical topology structure.
13. An LED according to claim 12 , wherein the LED chip includes: an n-type GaN structure; an n-type electrical contact adjacent a surface of the n-type GaN structure; an active layer having at least one quantum well on the n-type GaN structure; a p-type GaN layer on the active layer; a transparent conductive layer on the p-type GaN layer; and a p-type electrical contact on the transparent conductive layer.
14. An LED according to claim 13 , wherein the p-type electrical contact forms the first electrical contact and the n-type electrical contact forms the second electrical contact.
15. An LED according to claim 13 , wherein the n-type GaN structure includes an n-type GaN buffer layer.
16. An LED according to claim 3 , wherein the inner passivation includes SiO 2 .
17. An LED according to claim 3 , wherein the inner passivation includes Si x N y .
18. An LED according to claim 1 , further including a package the environmentally protects the LED chip.
19. A method of fabricating a white-light LED, comprising: procuring an LED chip that emits blue-light at a first wavelength, wherein the LED chip includes a first electrical contact and a second electrical contact; forming a yellow thin-film layer over the LED chip; and producing light having at least a second wavelength by passing electrical current through the first and second electrical contacts.
20. A method of fabricating a white-light LED according to claim 19 , wherein forming the yellow thin-film layer is performed by depositing a material selected from a group consisting of ZnSe, CeO 2 , Al 2 O 3 , and Y 2 O 3 :Ce.
21. A method of fabricating a white-light LED according to claim 20 , wherein forming the yellow thin-film layer is performed by chemical vapor deposition.
22. A method of fabricating a white-light LED according to claim 21 , wherein the chemical vapor deposition process is selected from a group consisting of metal organic chemical vapor deposition (MOCVD), atomic layer chemical vapor deposition (ALD), plasma enhanced MOCVD, plasma enhanced ALD, low pressure CVD, photo enhanced CVD and CVD.
23. A method of fabricating a white-light LED according to claim 21 , wherein chemical vapor deposition is performed using a metal precursor of a metal halide.
24. A method of fabricating a white-light LED according to claim 21 , wherein chemical vapor deposition process is performed using a metal organic precursor.
25. A method of fabricating a white-light LED according to claim 21 , wherein chemical vapor deposition is performed using a material selected from a group consisting of Alkoxide, -dikeonate, Metalloscene, Alkys, DMZn, DEZn, H 2 Se, DMSe, TbuSe, and DESe.
26. A method of fabricating a white-light LED according to claim 21 , further including the step of forming an inner passivation layer between the LED chip and the yellow thin-film layer.
27. A method of fabricating a white light LED according to claim 26 , wherein forming the inner passivation layer includes forming a SiO 2 layer.
28. A method of fabricating a white light LED according to claim 26 , wherein forming the inner passivation layer includes forming a Si x N y layer.
29. A method of fabricating a white light LED according to claim 21 , further including forming an outer passivation layer over the yellow thin-film layer.
30. A method of fabricating a white light LED according to claim 21 , further including bonding a first bonding wire to the first electrical contact and bonding a second bonding wire to the second electrical.
31. A method of fabricating a white light LED according to claim 21 , further including sealing the LED chip in a package.
32. A light emitting diode (LED), comprising: an LED chip having a first electrical contact and a second electrical contact, wherein the LED chip emits light having a first wavelength in response to an applied electrical power; and a tinted thin-film layer over the LED chip; wherein the tinted thin-film layer interacts with the first wavelength light to produce a second wavelength.
33. An LED according to claim 32 , wherein the tinted thin-film layer is selected from a group consisting of ZnSe, CeO 2 , Al 2 O 3 , and Y 2 O 3 :Ce.
34. An LED according to claim 32 , further including an inner passivation layer between the tinted thin-film layer and the LED chip.
35. An LED according to claim 32 , wherein the first wavelength light is converted to white light.
36. An LED according to claim 32 , further comprising an outer passivation layer over the tinted thin-film layer.
37. An Led according to claim 32 , further comprising a first bonding wire connected to the first electrical contact and a second bonding wire connected to the second electrical contact.
38. An Led according to claim 32 , wherein the LED chip has a lateral topology structure.
39. An Led according to claim 32 , wherein the LED chip has a vertical topology structure.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
December 11, 2002
June 1, 2004
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